1. Field of the Invention
The present invention relates generally to motion picture film projectors, and more particularly to a shutter assembly for carrying a film shutter into and out of alignment with a motion film projector aperture block.
2. Description of the Background Art
Motion picture film generally consists of a succession of still images or frames, which are sequentially projected onto a surface to produce the illusion of motion. Motion film projectors are, therefore, configured to transport each frame from a feed reel or spool to an aperture block, where the frame is held in stationary register for a period of time required for projection of the associated image. The frame is thereafter transported to a take-up. reel or spool. Similarly, a motion film camera is configured to transport each unexposed frame from a first location to the aperture block, where the frame is held in stationary register during exposure of the frame, and thereafter to a second location in the camera.
One motion film projector design is described in U.S. patent application Ser. No. 09/193,373, entitled System and Method for Transporting Film and Motion Film Projector Utilizing Same, filed Nov. 17, 1998. This design includes a plurality of shutters disposed on a moving linear conveyor for selectively shuttering a projector aperture block and for transporting the film across the aperture block. In one embodiment, the linear conveyor is a timing belt driven by toothed conveyor sprockets, which advance the shutters into and out of alignment with the aperture block at high speeds (48 shutters per second).
A need exists to provide a system and method by which a shutter may be reliably and securely mounted on a film projector conveyor such that the shutter is substantially stable. Moreover, a need exists to provide a shutter assembly that is adapted to carry a shutter over both straight and arcuate portions of a shutter travel path. An additional need exists for a shutter truck assembly that permits a shutter to be securely mounted on a toothed conveyor.